Statistical process control (SPC) typically entails the application of statistical methods to monitor and control a process to ensure that the process operates at its full potential to produce conforming product. Under SPC, a process may behave predictably to produce as much conforming product as possible with the least possible waste. While SPC has been applied most frequently to controlling manufacturing lines, it applies equally well to any process with a measurable output.
In general, SPC can be used to examine a process and the sources of variation in that process using tools that give weight to objective analysis over subjective opinions and to determine the strength of each source numerically. Variations in the process that may affect the quality of the end product or service can be detected and corrected, thus reducing waste as well as the likelihood that problems will be passed on to a customer. With an emphasis on early detection and prevention of problems, SPC generally has a distinct advantage over other quality methods, such as inspection, that apply resources to detecting and correcting problems after they have occurred.